METHOD FOR FORGING INTEGRAL TYPE CRANK-SHAFT

摘要

PROBLEM TO BE SOLVED: To provide a method for forging an integral type crank-shaft with which a suitable shape in the initial stage blank can be decided before forging. SOLUTION: This method for forging the integral type crank-shaft includes : a step (S1) for uniformly imparting a margin for machining surrounding the product-shape; a step (S2) for drawing an imagined ellipse as the center to the center portion of a pin shaft and a journal shaft so as to contain the whole shape imparting the machining margin; a step (S3) for calculating the forging load based on the imagined ellipse; a step (S4) for supposing the diameter and the length of the initial stage blank by considering the machining margin on the product shape; a step (S5) for obtaining the predicting ellipse with the calculation based on the front-stage diameter and length; a step (S6) for comparing the predicting ellipse and the imagined ellipse; a step (S7) for returning back to the step before two by changing the length when the difference having error set to both or more exists; and a step (S8) for deciding the suitable diameter and length of the initial stage blank. COPYRIGHT: (C)2008,JPO&INPIT